September 23, 2002

Journal of Occupational and Environmental Medicine, 2003

Workplace Accommodations for People with Disabilities: National Health Interview Survey Disability Supplement, 1994-5

Running Title: Work Accommodations for Persons with Disabilities

Craig Zwerling, MD, PhD, MPH1, Paul S. Whitten, MA1, Nancy L. Sprince, MD, MPH1, Charles S. Davis, PhD3,Robert B. Wallace, MD, MS1, Peter Blanck, JD, PhD2, Steven G. Heeringa, PhD4

From the University of Iowa, College of Public Health1, College of Law2, Elan Pharmaceutical Company3s3, and The University of Michigan Survey Research Center4

Corresponding author: Craig Zwerling, MD, PhD, MPH. The University of Iowa, College of Public Health, 100 Oakdale Campus, #126 IREH, Iowa City, Iowa, 52242-5000.

Funded by the National Institute on Aging (5R01 AG 16829) with additional support from the National Center for Injury Prevention and Control (R49ICCR 703640). Also supported in part by funding to Peter Blanck from the U.S. Department of Education, the National Institute on Disability and Rehabilitation Research (HLI 33 B 980042-99),and (H 133A 011 1803), (H133A021801); The Great Plains ADA and IT Center; and The University of Iowa College of Law Foundation.

Abstract

As American workers age, workers with impairments and functional limitations make up a larger percentage of our workforce. This investigation presents data from the National Health Interview Survey Disabilityities Supplement 1994-1995 (NHIS-D) describing the nature of workplace accommodations in the American workforce and factors associated with the provision of such accommodations. Of a nationally representative sample of workers, aged 18 to 69 years with a wide range of impairments, 12% reported receiving workplace accommodations.. M Males (Odds odds Ratio ratio 0.64: (95% Confidence confidence Intervalinterval) 0.64 ( 0.53-0.78) and Southerners (OR 0.57; 95% CI(0.47-0.70) were less likely than others to receive workplace accommodations. Those with mental health conditions were less likely than others to receive accommodations (OR 0.56; 95% CI 0.44-0.70). College graduates (OR 1.53; 95% CI(1.22-1.91)), older workers, full time workers (OR 3.99; 95%(CI 2.63-3.87), and the self-employed (OR 1.76; 95% CI(1.28-2.41) were more likely than others to receive accommodations. Those with mental health conditions were less likely than others to receive accommodations (OR 0.56; 95% CI (0.44-0.70).

Over the next decades, the proportion of American workers with disabilities is can be expected to increase for several reasons, including: the aging of the American workforce and the impact of policy changes in healthcare and welfare reform.[1]

The Bureau of Labor Statistics data suggest that the average age of workers will increase,, as baby boomers who were born between 1946 and 1964 reach their 50s and 60s, the workforce will age. The median age of American workers increased from 35 in 1978 to 39 in 2000 and is expected to reach age 41 by 2010.[2],[3] Fullerton and Toossi2 suggest that, from 2000 to 2010, the number of American workers aged 55 and older will increase by 47%.

With age, the prevalence of disability increases.[4] The National Health Interview Survey (NHIS) (1994) likewise suggests that with age the percentage of workers with disabilities will increase.4 Among workers 18-28 years of age, 3.4% work with disabilities; among those 50-59 years of age, 8.4%; and among those 60-69 years of age, 13.6%. Thus, the aging workforce will include more people working with disabilities.

In addition to the demographic pressure from the aging baby boomers, the Americans with Disabilities Act (ADA)[5] was expected to increase the number of qualified workers with disabilities in the American workforce.1 Recent findings are mixed in this regard.[6],[7], 8

Some studies report that the employment levels of individuals with work disabilities, but not necessarily with conditions covered by the ADA, have declined in the early 1990s. Other research finds improvements in employment since the ADA was passed, but again, not necessarily for individuals covered by the law. [8]

The ADA provides that employers with 15 or more employees must make “reasonable” accommodations for “qualified” workers with disabilities to participate in the workforce. The ADA’s accommodation requirement mandates that an employer provide benefits to, or take steps in response to, the needs of particular qualified individuals so they are able to perform essential job functions.[9]

Other recent policy innovations are aimed at diminishing economic barriers that prevent persons with disabilities from working. For example, the Ticket to Work and Work Incentives Act of 1999 (TWWIIA) makes affordable health care coverage available to qualifying individuals with disabilities. Also, the Workforce Investment Act of 1998 (WIA) establishes “one stop” employment and job training centers to provide accessible services and supports for all workers, including those with disabilities.3, 6,[10]

Our recent empirical work[11],[12],[13] suggests that a broad spectrum of workers with disabilities, though not necessarily those covered by the ADA or other disability schemes, are at increased risk for occupational injuries. We found this increased risk among older workers of the Health and Retirement Study12,13as well as among workers of all ages surveyed by the NHIS11.The increased risk of occupational injury was found in cross-sectional studies12as well as in prospective cohort studies13.

As workers with impairments and functional limitations make up a larger percentage of our workforce, occupational injuries are likely to increase unless employers provide effective workplace accommodations that lower the risk of injury. However, there is little national data on the prevalence of and nature of workplace accommodations.[14] This investigation presents data from the NHIS Disabilityies Supplement 1994-1995 (NHIS-D) describing the nature of workplace accommodations in the American workforce and factors associated with the provision of such accommodations.

Methods

The Cohort

Our study population derives from the National Health Interview Survey Disability Supplement, 1994-1995. The National Health Interview Survey is an annual survey of the health status of Americans, carried out by the Census Bureau under contract from the National Center for Health Statistics. From 1994 to1995, in addition to the regular core questions, the Census Bureau administered two more detailed surveys (the Disability Follow-back Surveys) to obtain more information on the health and social status of Americans with disabilities.

Eligibility for the Disability Follow-Back Survey was determined by a positive response to any of nearly 200 screening questions. The Disability Follow-Back Surveys collected self-reported information regarding need for assistance with key activities, difficulties with activities of daily living (ADLs), instrumental activities of daily living (IADLs), and functional limitations. Additionally a broad range of medical, social, and employment information was collected. Eligibility for the Disability Follow-Back Survey was determined by a positive response to any of nearly 200 screening questions.

Our study population included those with who reported a variety of impairments and functional limitations. We included those who had: difficulty with ADLs (bathing, dressing, eating, getting in or out of bed or chair, or using the toilet); difficulty with IADLs (preparing own meals, shopping for personal items, using telephone, doing heavy work around the house, and or doing light work around the house); functional limitations (lifting 10 lbs., walking up 10 steps, walking a quarter mile, standing for 20 minutes, bending down from a standing position, reaching over the head, using the fingers to grasp or handle something, or holding a pen or pencil); difficulty seeing, (even with their glasses); ordifficulty hearing, (even with a hearing aid); reported mental health or cognitive diagnoses (Down’s Syndrome, mental retardation, schizophrenia, delusional disorders, bipolar disorder, major depression, severe personality disorder, alcohol abuse, drug abuse, other mental or emotional conditions); or rand reported the use of a cane, crutches, walker, wheelchair or scooter to get around.

Of the 25,805 participating respondents to the Disability Follow-Back Surveys over the two years, 47% (12,151) met at least one of the 31 inclusion criteria and were between 18 and 69 years old at the time of the survey. We have previously reported on the factors associated with employment among these 12,151 respondents with impairments.[15] In this investigation, we report on the 41% (4,937) of these respondents who were working at a job or business at the time of the survey. They constitute a representative sample of working Americans with impairments and functional limitations. Those who were not employed were not included in the study.

Variables

The outcome variables of interest are derived from questions in section D of the Disabilty Follow-Back Surveys that asked the respondent: " “In order to work would you need any of these special features at your work site, regardless of whether or not you actually have them.?”” The respondents are then asked: " “Do you have (feature) at work?" ?” The questionnaire offers the respondent the 17 specific accommodations listed in Table 1.

Our primary dichotomous outcome variable compares respondents who report receiving any accommodation to those who report receiving no accommodation. No employment records were available to validate these self-reports. We also do not know whether any of the reported accommodations would be required by the ADA.

Potential predictors of the provision of accommodation were considered in three categories. First, we considered background variables related to the worker: age, race, ethnicity, sex, education, income, region of residence, and urban/non-urban (>100,000 population). Second, we considered job-related variables: number of hours worked, self-employment status, standard occupational and industrial codes associated with the worker's employment. Third, we considered individual health and impairment variables. These included a self-rating of general health, duration of limitation, self-reported difficulties with IADLs, ADLs, or functional limitations. Severe sensory limitations included were: difficulty seeing even while wearing glasses, or difficulty hearing even while wearing a hearing aid. Diagnosed physical conditions causing difficulties with ADLs and measures of severity of impairment were considered in this final category.

Standard occupational codes are compared to the executive/professional group; standard industrial codes are compared to the manufacturing group. Self-reported health status is classified as excellent or good compared to fair or poor. The specific functional limitations include: any difficulty walking a quarter-mile, sitting two hours, lifting or carrying 25 pounds, lifting 10 pounds, walking 10 steps without resting, standing two hoursfor twenty minutes, stooping, kneeling, or bending, reaching overhead, reaching out as if to shake hands, or using fingers to grasp. Only difficulties that subjects expected to last at least twelve months were classified as "yes".

Difficulties with ADLs and IADLs include: bathing, dressing, eating, getting in or out of bed, any difficulty walking, or difficulty managing money. These variables are dichotomized as “yes” for any difficulty and “no” for none. Severe hearing problem is defined as "having difficulty hearing normal conversation even while wearing a hearing aid" while severe vision problem is defined as "difficulty seeing even while wearing glasses."

To assess the severity of impairments, two measures of severity are reported in the literature. The first measure, constructed by Kasper et al.,[16] grouped the functional limitations into four "domains.". These domains consist of difficulties in the upper extremities, mobility or exercise tolerance, higher functioning, and basic self-care. The number of domains affected ranging from zero to four measuredcan be used to estimate the severity of the functional limitation. For analytical purposes, we used zero as the reference category in the regression model.

The second measure, constructed by Loprest, Rupp, and Sandell,[17] created a seven point scale to represent the degree of difficulty within four categories of functions: basic functions, sedentary work functions, physical work functions, and very physical work functions. The scaling of the responses, and some of the questions themselves, are slightly different between the HRS and the NHIS-D for the questions regarding functional limitations. We developed a parallel five-point scale to reflect presence and severity of work function limitations. The categories represented are basic sedentary functions, minimal mobility or strength functions, and vigorous mobility or physical strength functions that might be required while on the job. With this scale, category five represents the most seriously impaired while category one represents respondents with no functional limitation. We use one as the reference category in the regression model.

Medical conditions primarily causing difficulty with the ADL were categorized as cardiovascular, musculoskeletal, respiratory, sensory, and other conditions based upon diagnostic codes (see Baldwin).[18] We included three subsets of the musculoskeletal conditions: those of the back or spine, the upper extremities, and the lower extremities. Mental health and cognitive conditions included schizophrenia, paranoid delusional disorder, bipolar disorder, major depression, severe personality disorder, alcohol abuse, drug abuse, and other mental or emotional disorders.

Analysis

We compared those who self-reported receiving workplace accommodations to those who did not. First, we examined the bivariate associations between our predictive variables and the provision of accommodations. Second, we constructed a logistic regression model including those variables related to the worker demography and the job that were associated (p<0.05) with the provision of accommodations. This base model allowed us to assess the relative importance of these variables in predicting the availability of accommodations. Third, we added each of the variables describing limitations and health conditions individually to the base model to assess their relationship with workplace accommodation after controlling for key variables concerning the workers and their job.

The NHIS is a multistage, stratified, clustered sample weighted to represent the number of non-institutionalized adults in the United States. To account for the complex structure of this sample, we used SUDAAN software[19] to estimate standard errors and corresponding confidence intervals for odds ratios.

Results

Our cohort consisted of 4,937 Americans working with functional self reported impairments and/or functional limitations. They ranged from 18 to 69 years of age with a mean age of 43.0. Forty-eight percent were men; 88% were white; 43% has had at least some college education; 49% had a family income of $35,000 or more. Hence, this sub-sample generally is comprised of white men and women who tended to be educated and with family incomes above poverty levels. The first three columns in Table 2 providess additional description of our cohort.

Table 1 describes the proportion of our study population, who report needing needing any of 17 specific accommodations and the proportion who report receiving these accommodations. Of the 4,937 individuals in our study population, a relatively small proportion, (771 or 16%), reported needing any of the 17 accommodations. Likewise, a small proportion (602 or 12%) reported receiving at least one accommodation. However, the majority (78%) of those who reported needing an accommodation received it from their employers (78%).

The most common accommodations provided received included accessible parking or accessible transportation, (4.2%); an elevator, (3.1%); a workstation specifically designed for your use, (3.1%); handrails or ramps, (2.2%); and reduced or part-time hours, (2.1%).

Table 2 summarizes the bivariate associations between our set of predictors and self-reported provision of workplace accommodation. The number with the risk factor, and the number and percent accommodated are unweighted while the odds ratios and associated 95 percent confidence intervals reflect the complex sample design of the NHIS and weighted analysis using SUDAAN software.

From Table 2, we observe that both younger workers (aged 40 years and younger) and older workers (aged 61 years and older) were significantly less likely to report the provision of accommodations than are workers aged 41-51 50 years. Males report significantly fewer accommodations than females. There is was no statistically significant difference identified among racial groups or among those of Hispanic ethnicity.

Those with at least some college education report increased provision of accommodation. Compared to workers in the Northeast region of the United States, those in the South reported fewer accommodations. Those living in urban areas reported more accommodations than those living in non-urban areas. Compared to the executive professional group, those in sales, service occupations, mechanics, machine operators, and transport handlers report fewer accommodations. Compared to those in manufacturing, those in agriculture, mining, construction, retail/wholesale trade and transport or public utilities report fewer accommodations. Those in insurance/real estate, personal services, professional services, and public administration report more accommodations. Those in insurance/real estate; professional service; and public administration report more accommodations. Full-time workers are significantly more more likely to report a workplace accommodation.

Reported difficulty with any of the ADLs, functional limitations, or IADLs is associated with an increased self-reported availability of accommodation (not presented). Using either Kaspar’s or Loprest’s measures of severity of limitation, we observe a clear dose response effect: the more severe the limitation, the more likely receiving an accommodation is reported. Those reporting physical limitations of longer duration (dating from 1990 or earlier) are more likely to have accommodations than those recently limited. Those with severe hearing problems are significantly less likely to report an accommodation. Workers with mental health disabilities are almost one half less likely to receive accommodations than workers with other disabilities. Specifically, those workers with diagnosed major depression or substance abuse disorder are significantly less likely to report accommodations.

Table 3 presents the adjusted odds ratios and confidence intervals from the base logistic regression model including demographic predictors of accommodation. This model shows slight changes in odds ratios from the bivariate analysis. Age, sex, education, region of residence, occupation and full-time work status remain significant predictors of accommodation. A Hosmer-Lemeshow[20] goodness-of-fit test yields a p-value of 0.70 indicating that the base model seems to fit quite wellan adequate fit for the base model.

Table 4 presents the associations between workplace accommodations and the specific functional limitations and medical diagnoses. In this model, we enter variables individually after controlling for the demographic factors in the base logistic regression model. As in the bivariate analysis, self-rating of excellent or good health and a recent onset of limitation are associated with a reduced likelihood of accommodation.